GST/HST Invoice Setup in BoltBill Pro: A Software Guide

To issue a compliant GST/HST invoice in Canada, your document must clearly display your 15-digit CRA Business Number, the date, total fee, applicable tax rates, total tax charged, and the buyer's business name. Under the Excise Tax Act, the tax rate charged depends on your client's location or site address under specific place-of-supply rules.

Essential Requirements for Canadian Tax Invoices

The Canada Revenue Agency (CRA) enforces strict documentation requirements under Section 223 of the Excise Tax Act. For professional service invoices exceeding $150.00, missing a single mandatory field can lead to your client's Input Tax Credit (ITC) being rejected during an audit.

Every tax invoice you issue for engineering, architectural, drafting, or technical consulting services must explicitly state:

• Business Identity: Your registered business name (or operating name) and your 15-digit GST/HST registration number (e.g., 12345 6789 RT0001).
• Client Identification: The client's full legal name or trade name.
• Transaction Details: Invoice date, unique invoice number, and a concise description of services rendered (e.g., "Structural Engineering Phase 2 – Issued for Construction Drawings").
• Tax Breakdown: The total amount payable, the specific rate applied (5% GST, 13% HST, or 15% HST), and the exact dollar amount of tax charged. Alternatively, you may explicitly state "Total includes GST/HST at [rate]%".

If you bill client practices operating in Quebec, provincial rules require showing your 10-digit Revenu Québec QST number alongside your federal GST number whenever QST is applicable.

Place of Supply Rules for Professional Services

Determining which provincial tax rate to bill is governed by Schedule IX to the Excise Tax Act. For professional service firms, two main rules apply depending on whether your work relates directly to real property.

General Professional Services Rule

For general technical consulting, reports, drafting, or off-site studies, the place of supply is primary to the location of the client's business address obtained in the ordinary course of business. If a consultant in Calgary prepares a mechanical design report for a client headquartered in Toronto, the place of supply is Ontario. The consultant must bill 13% HST, not 5% Alberta GST.

Real Property Rule

When engineering or architectural services relate directly to specific real property (such as site planning, structural inspections, or construction administration), the place of supply defaults to the physical location of the land or building. If an architect based in Halifax designs an office building situated in Saint John, New Brunswick, the service is subject to New Brunswick's 15% HST rate because the land resides in New Brunswick.

Worked Calculation: Out-of-Province Fee with Holdback

Consider an engineering firm located in British Columbia performing structural inspection services for a commercial developer located in Ontario. The agreed fixed fee for the billing period is $10,000.00. The project site is in Ontario, making the supply location Ontario (13% HST).

Under provincial construction lien legislation (such as Ontario's Construction Act, Section 22), clients routinely retain a statutory 10% holdback from progress payments. A common accounting mistake is calculating tax on the net payment after holdback. The CRA requires GST/HST to be calculated on the full gross value of services billed prior to holdback retention.

Notice that the full $1,300.00 HST is collected on the gross fee. The client retains $1,000.00 of the principal fee, releasing it only upon expiration of the lien period. Tracking these split receivables manually in generic billing tools often leads to tax reporting errors, which is why platforms built specifically for professional practices, such as BoltBill Pro, isolate holdbacks from GST/HST sub-totals automatically.

Common Billing Failures in Engineering Practices

Audit exposure in Canadian engineering and architectural firms typically stems from three systemic errors:

1. Applying Home Province Rates: Charging your local provincial rate on work performed for out-of-province clients. The tax engine must evaluate client location and property location for every fee schedule.
2. Improper Handling of PST/QST: In provinces like Saskatchewan (6% PST) or British Columbia (7% PST), certain services may attract provincial sales tax alongside GST. In Quebec, QST (9.975%) applies on top of the base amount, calculated independently of GST.
3. Failing Record Retention Requirements: Subsection 286(1) of the Excise Tax Act mandates that practices retain all tax invoices, billing ledgers, and proof of payment for six years from the end of the relevant tax year. Digital copies are acceptable provided they are readable and accessible.

You can review detailed regional breakdowns on the BoltBill blog for specific provincial tax rules across architectural and engineering disciplines.

Pre-Flight Invoicing Checklist

Before issuing your next progress billing or fee statement, verify your document against these operational standard requirements:

• Is your 15-digit CRA Business Number clearly printed?
• Does the invoice name match the client's legal entity name?
• Did you apply the correct tax rate based on the place-of-supply rule rather than your office address?
• Is GST/HST calculated on the gross professional fee before deducting lien holdbacks?
• Are tax amounts listed separately from subtotal service fees?
• Will this invoice be archived in a system that guarantees 6-year retention compliance?

Consulting practices that verify these six items before sending invoices eliminate audit friction and prevent delayed client payments caused by invoice rejections. To evaluate software designed around these exact workflows, review our pricing for practice-wide deployment options.